Marc Márquez and Alex Márquez went toe-to-toe in the feature race in Argentina, with Marc Márquez leading early on, before relinquishing first to Alex and then regaining his place at the front late on to take his second victory of the season.
Alex finished second to further secure his best start to a MotoGP season yet.
Pecco Bagnaia finished fourth and Pedro Acosta eighth; both Alpinestars riders.